Growth inhibition of leukaemic cells carrying the t(3;21) by the AML1/EVI-1-specific antisense oligonucleotide.

The t(3;21)(q26;q22) translocation is thought to play an important role in the acute phase transformation of CML. The formation of the AML1/EVI-1 fusion gene by the translocation leads to expression of the AML1/EVI-1 fusion protein. Here we demonstrate that the AML1/EVI-1-specific antisense oligonucleotide markedly decreases the [3H]thymidine incorporation and growth of leukaemic cells carrying the t(3;21) and the t(9;22), but not those of K562 cells. These results indicate that the AML1/EVI-1 fusion protein could contribute to proliferation of the t(3;21)-carrying leukaemic cells after entering the blastic crisis phase of CML.